CEFEP Technical Blog

Condensation on pipework should always be prevented wherever possible. Moisture formation can damage the structural fabric of a building, promote mould growth and either cause or greatly accelerate pipe corrosion. In extreme circumstances corrosion attributed to condensation can even shorten the lifespan of a mechanical system.

Insulation is used to ensure that the surface temperature remains above the critical dew-point temperature so that condensation cannot form. “The properties of the insulation play an important role in preventing condensation and closed-cell materials have a clear advantage,” explains Ralf Springub from the European FEF/PEF Interest Group CEFEP (Celle, Germany).

Warmer air can hold lots of moisture as water vapour but this capacity is diminished as it cools. Eventually cooling air must relinquish some of the moisture it could hold at higher temperatures, creating what we know as condensation. Any surface cooler than the surrounding air presents the potential for condensation but the risks are greater as the temperature decreases, making it a particular issue for refrigeration and air-conditioning pipes.

Fortunately pipe insulation doesn’t just reduce energy loss – it can also be used to prevent the warm, moisture laden, air coming into contact with the cold surfaces of refrigeration and air-conditioning pipework.

Better in black

“The properties of an insulation material are important when assessing its suitability for refrigeration and air conditioning pipework,” explains Ralf Springub, “it’s essential to keep the surface temperature above the dew-point so that condensation cannot form”. Besides the specific thermal conductivity, the surface emissivity of the insulation material is critical. The surface emissivity describes the potential of a material to give off energy in the form of thermal radiation etc. With a non-reflective, high emissivity finish, black surfaces are well suited to controlling the surface temperature. In this way, relatively low insulation thicknesses can be used for the reliable control of condensation.

Keep water vapour out of insulation and off the pipe

Differences in partial water vapour pressure force moisture towards cold surfaces. If water vapour is free to pass through the insulation surface it can cause interstitial condensation within the material, dramatically reducing energy saving performance and increasing the risks of pipe corrosion.

For many insulation materials the only way to prevent this is to apply an external water vapour barrier – usually in the form of a thin and easily damaged Aluminium foil. Closed cell FEF and PEF materials are, however, so inherently effective at preventing the passage of water vapour that they can be considered to possess an in-built water vapour barrier and do not require an external foil to be applied.

The nature of this resistance means that surface damage to a closed cell FEF or PEF insulation material is unlikely to significantly impair or diminish its ability to prevent condensation moisture ingress.

Maximising flexibility, minimising thickness

Because FEF and PEF insulation materials are not reliant on an low-emissivity external water vapour barrier they are able to present a high emissivity surface finish. This can lead to notably thinner insulation solutions for controlling condensation when using FEF or PEF materials.

FEF insulation materials are particularly practical when it comes to insulating irregularly shaped pipework elements like valves and flanges. Thanks to the flexibility of the foam and the inherent water vapour resistance offered by the closed cell structure, FEF materials can be easily shaped and cut to size and aren’t reliant on a externally applied water vapour barrier for protection against moisture ingress.

keep reading ...

Manufacturers have been obliged to guarantee that their products conform to the requirements of the Construction Products Regulation (CPR) since the legislation was first introduced. Among other requirements a manufacturer must issue a declaration of performance.  This is an integral part of the CE marking process.

Only CE marked products can be marketed in the European trading area. The leading manufacturers of technical insulation materials made of flexible elastomeric foams (FEF) and polyethylene foams (PEF) ensure that their products display the CE mark.

The European FEF/PEF Interest Group, “CEFEP”, strongly supports CE marking.  CEFEP also promotes harmonised standards and provides a definitive source of information from the FEF/PEF insulation industry.

CEFEP was founded in the year 2013 and the ideal of replacing older conflicting, country specific, standards with harmonised European standards has always been close to the heart of the organisation. Today all members produce technical insulation materials which are approved for use in Europe and bear the CE mark. With the CE mark in place, CEFEP manufacturers confirm that their products meet the relevant EU regulations.

The principal standards for FEF and PEF insulation

A CE mark is not a mark of quality but, rather, an acknowledgement that the manufacturer has declared the “essential characteristics” of that product.  The properties that must be declared and the rules for declaring them are defined in a series of European standards.
Two standards are of fundamental importance: EN 14304 is applied for thermal insulation materials that are made of flexible elastomeric foams (FEF) for building equipment and industrial installations. EN 14313 refers to insulation products consisting of polyethylene foams (PEF).
In the case of technical insulation materials, a further distinction is made between flat products (insulating panels) and linear products (hoses).
Information on the thermal conductivity (λ-value) and the fire behaviour is obligatory in both categories. Data on the water vapour diffusion resistance (μ-value) and the release of corrosive substances also play a role for the assessment of the materials and these are often included in the declaration of performance.
Both product standards require inspection methods for factory production control (FPC) and preliminary technical determination (PTD).

Inspiring confidence for users

The CPR and the introduction of harmonized European product standards represents a fundamental change for the construction sector. With the introduction of CE marking it is now necessary to use the same methods of inspection and assessment throughout Europe, removing a potential barrier to international trade within the EU.
For consultants, wholesalers and installers, CE marking makes it easy to compare a wide range of products from different manufacturers. CEFEP members aim to provide all of the information required by EN 14304 and EN 14313 in an unambiguous way to a high level of precision.

Uniform European fire classification

The new European fire classes (A to F), defined within EN 13501-1, are a mandatory part of the EN 14304 and EN 14313 product standards. A European fire classification must be declared for a product as part of the CE marking process.
To classify flammable insulation materials, EN 13501-1 specifies that the SBI (Single Burning Item) testing method should be used. This assesses the contribution that the construction product in question makes to the development of a fire.
Linear products (tubes) are additionally marked with a subscript “L”. Another new feature is the testing of the smoke development using the abbreviation “s” (for “smoke”) and “d” (for “droplets”) in the case of burning droplets. European class E is tested by means of the ignitability test according to EN ISO 11925-2.
In order to offer its customers the greatest possible clarity when selecting technical insulation materials, the members of CEFEP all provide declarations of performance. “With regard to the declarations of performance for our products, we want to create as much transparency as possible and thus achieve a high degree of security in product selection,” confirms Georg Eleftheriadis, chairman of the “Gütegemeinschaft Hartschaum” and chairman of the CEFEP. “We are glad to support dealers, planners and users with our advice.”

keep reading ...

Technical insulation materials made of flexible elastomeric foams (FEF) and polyethylene foams (PEF) are among the few industrial products which actually save more energy during their service life than they require for their manufacture. As a result, they can help to meet the latest EU energy consumption reduction targets.

At a local, national and international level, Europe today stands poised to undertake the biggest "energy transition" in more than a century. With ambitious EU commitments to reduce greenhouse gas emissions by more than 40 percent by 2030 and achieve a 27 percent increase in energy saving over the same timeframe, insulation will play an increasingly important role and nowhere will the effects be more felt than in the construction industry.

Buildings currently consume around forty percent of all the energy used within Europe. With space heating and cooling accounting for the majority of this the countries of the EU have tightened their demands on the primary energy requirements of buildings.

Increased levels of structural insulation ensure that buildings retain heat more reliably but there has also been a focus on improving the efficiency of heating, cooling and ventilation systems. Insulation materials made of flexible elastomeric foams (FEF) and polyethylene foams (PEF) offer a sustainable way to reduce the energy use of these systems.

Study shows positive ecological balance

Industrially manufactured products require raw materials and energy for their production but technical insulation materials are a special case as they save energy over the course of their service life. Studies carried out by member companies of the CEFEP Interest Group have demonstrated that FEF pipe insulation materials have a net positive effect.

Energy efficiency of technical insulation materials

The analysis shows that the energy requirements for supplying an average residential building with hot water and heat can be reduced by up to 25 percent by installing an optimal thickness of pipe insulation.

Technical insulation materials made of flexible elastomeric and polyethylene foams are highly recommended due to their consistent long-term efficiency and short payback times. "Thanks to their closed-cell structure in conjunction with their low thermal conductivity, synthetic insulation materials help to reduce energy consumption in buildings," Dominique Malache explains. "In many cases, the insulation of pipes, fittings and pipe clamps pays off after just a few weeks."

Increasing demand in air-conditioning

When it comes to insulating air-conditioning pipes the temperature on the surface of the material must be above the dew point at all times in order to prevent the formation of condensation that could otherwise result in pipe corrosion.

 Although this is the main reason to insulation these pipes, there are energy saving benefits too and investing in technical insulation materials soon pays off. “Protection from energy loss and prevention of condensation go hand in hand,” is how Dominique Malache sums up the situation. The global demand for air-conditioning technology continues to rise – forecasts even say that the demand could triple by 2030.

keep reading ...

Mind the gap(s) to unleash additional saving potential

Energy losses from un-insulated fitting are so great that it’s not possible to “make-up for them in any other way.


Condensation Control

Learn more about how to prevent condensation forming on cold, 
refrigeration and air-conditioning pipes.

Subscribe to our newsletter

Once per month we send you an update of our latest post about the insulation of mechanical services